Question

__________ was described as the "number of unique or useful pieces of information we have when estimating population parameters."

1. 		Sample size
   		Significance level
   		Degrees of freedom
   		Standard error

1. In which of the following research situations, it is appropriate to use a matched-paired samples t-test as opposed to independent samples t-test.

   		When there are same number of samples in the two conditions to be compared.
   		When one can assume there is a causal relation between independent and dependent variables.
   		When the same group of people contributed the data (measured dependent variables) twice under the two different conditions.
   		When two groups of samples are assumed to be independent.
   		When two groups of people to be compared are believed to be from the same ethnic group or genders

Answer 1

(1) Degrees of freedom, since it is the number of values in the final calculation of a statistic that is free to vary.

(2) When the same group of people contributed the data (measured dependent variables) twice under the two different conditions, since we are comparing two sets of paired data here.